1. Field of the Invention
The present invention relates to a cross country ski binding.
2. Description of Background and Relevant Information
In a well-known manner, a cross country ski binding comprises means for retaining the tip of the shoe on the ski. These retention means comprise a movable latching element adapted to selectively occupy either a position for blocking the tip of the shoe (in a manner so as to allow for cross country skiing), or a position for freeing the tip of the shoe (permitting either insertion of the shoe, i.e., the positioning of the shoe on the ski, in the binding--or removal of the shoe--i.e., release of the shoe --).
For simplicity and safety of use, modern bindings possess "automatic" shoe insertion means permitting the user to put on his skis without manual intervention. For this purpose, it suffices to appropriately position the tip of the shoe in the binding, to exert a force of the foot from top to bottom on the ski, which serves to achieve blockage of the tip of the shoe in the binding by means of an appropriate mechanism.
A modern binding for a cross country ski comprises furthermore elastic means such as springs or rubber bumpers positioned to resist the movement of the foot during skiing. This cyclical movement comprises lifting of the heel combined with a pivoting at the position of the tip of the foot as well as a flexion of the foot at the position of the metatarsus. The elastic means are generally positioned in the binding, in front of the tip of the shoe; they absorb and then return to each step a certain quantity of energy, which allows for a controlled movement of the shoe and of the foot during walking.
In previous French patent applications filed by applicant and not yet published, No. 90 02824 and No. 90 02825, these elastic means comprise a pair of flexion bars which extend symmetrically under the shoe, substantially parallel to the ski, on both sides of its longitudinal plane of symmetry, while being inserted in lateral grooves provided in the sides of the ski.
A design of this type has the advantage of substantially reducing the bulkiness of the portion of the binding which is positioned in front of the tip of the shoe (because this portion need no longer contain the elastic means) and to ensure a good distribution of the masses. Furthermore, the flexion bars are particularly efficient in their function of absorbing and restoring energy.